Apparatus for feeding continuous webs



July 7, 1964 c. J. FITCH APPARATUS FOR FEEDING commuous WEBS 2Sheets-Sheet 1 Filed Jan. 25, 1962 FIG. //Vl//VTOR CLYDE J. FITCH 5) 14,6. 01x9 ATTORNEY July 7, 1964 c. J. FITCH APPARATUS FOR FEEDING commuousWEBS 2 Sheets-Sheet 2 Filed Jan. 23, 1962 United States Patent 3,140,031APPARATUS- FOR FEEDING CONTINUOUS. WEBS Clyde J. Fitch, Endicott, N.Y.,assignor to International Business Machines Corporation, New York, N.Y.,a corporation of New York Fiied Jan. 23, 1962, Ser. No. 168,036 7Claims. (Cl. 226-109) This invention relates to apparatus for feedingcontinuous webs, and more particularly relates to apparatus forcontrolling concurrent intermittent feeding of. a plurality ofcontinuous webs, such as tape, ribbons, or the like.

Recently, considerable effort has been directed toward developinghigh-speed matrix printers, such as of the wire-printer type, whichprint in a mosaic pattern. In these printers, it is customary to advancea paper tape and a carbon ribbon incrementally in converging paths pasta print head, and print one character at a time while the tape andribbon are stationary. Printing, of each character is eifected bydriving appropriate ones of the individual solenoids for each printingelement of the matrix. When the appropriate solenoids are de-energized,the print elements are retracted. This enables the tape and ribbon to beincrementally advanced preparatory to the printing of the nextcharacter.

In order for the incrementally advanced paper tape to be printed at highspeeds, such as 100 characters per second, it is essential that theapparatus controlling the incrementing of the paper tape and carbonribbon be of low inertia and capable of rapid operation. It is alsodesirable that the control apparatus be relatively simple, compact andinexpensive and that it be capable of use in other applications besidethe printing field.

It is therefore one object of this invention to provide a compact,relatively simple, and inexpensive apparatus embodying a mechanism oflow inertia for controlling feeding of continuous webs.

Another object is to provide an apparatusof the above type forcontrolling incremental feeding concurrently of a plurality ofcontinuous webs of the same or different types.

Still anotherobject is to provide an apparatus of the above typeembodying a manually operable mechanism to facilitate insertion of webmaterial from a replacement source.

A further object is to provide an apparatus capable of feedingcontinuous webs without buckling the webs.

According to these objects, the apparatus comprises a singleelectro-magnet having an armature for controlling concurrent feeding oftwo separated continuous webs, such as a paper tape and a carbon ribbonwhich converge at a print station. A tape drive arm and a holder arelaterally secured to the armature so as to be pivotable thereby. Thepaper tape passes between a guideway defined between a stationary guideand a laterally extending tape-overlying finger of the drive arm. Thisarm carries a thin flexible tape drive pawl or pusher that projectsupwardly so as normally to pinch the tape against the under surface ofthe finger so the tape will be carried forward a predetermined distancewhen the magnet is de-energized. A flexible detent similar to the tapedrive pusher contacts the upper surface of the tape and resilientlypresses it against the guide to hold the tape against rear- 3,140,031Patented July 7, 1964:

ice.

ward movement when the finger and pusher are movedrearward byenergization of the magnet.

The carbon ribbonis fed-between the bite of a knurled drive; rollandta1pressure roll. When the magnet is deener-gized, theholden willadvance a pusher into-jabbing engagement with a ratchet wheel to rotateit a given increment. The knurled roll is keyed to the same shaft as theratchet wheel so that it will be rotated and thus feed the ribbonforward: a corresponding distance each time the magnet is de-energized.When the magnet is energized, the pusher is retracted from the ratchetwheel.

The finger of the tape drive pawl preferably has a rearwardly extendingprojection which overlies or overlaps a forwardly extending projectionof the guide, the extent of such overlap being greatest while the magnetis energized. This prevents buckling of the tape during rearward motionof the finger and associated pusher upon energization of the magnet.Also, a toggle-type mechanism preferably is provided for normallybiasing the pressure roll into contact with the knurled drive roll, butcapable of holding these rolls biased a preselected distance apart tofacilitate replacement of the ribbon.

The foregoing and" other objects, features and advantages-of theinvention will be apparent from the following more particulardescription of a preferred embodiment thereof, as illustrated in theaccompanying drawings, wherein:

FIG. 1 is a side elevation view of a web-feeding apparatus embodying theinvention;

FIG. 2 is an isometric view, to enlarged scale, of a ribbon. feedmechanism shown in FIG. 1; and

FIG. 3 is a perspective view, to enlarged. scale, of a tape drive pawland detent, also shown in FIG. 1.

As shown in FIG. 1', the web-feeding apparatus embodying the inventioncomprises an electro-magnet 10 including a coil 11 wound around one legof a U-shaped core 12. The core 12 is laterally secured, such as byscrews 13, to a fixed L-shaped member 14. The magnet has an armature 15which is pivoted at- 16. A helical spring 17, which biases the armatureaway from the pole face of the core, seats against respective springseats formed on the armature and at one end of a screw 18. This screw isadjustably positionable relative to the fixed member 14 to enablepreadjustment of the bias force of spring 17, after which the screwpreferably is locked in desired position by a lock nut 19'.

This. single magnet 10 controls concurrent incremental feeding of twocontinuous webs. in the manner now to be described. As illustrated,these web's are a paper tape T and a carbon ribbon R which are adaptedto be fed in the direction of arrows 20, 21, respectively.

The tape T passes over a guide surface 22 provided by the flat uppersurface of a lateral projection or flange forming part of an invertedL-shaped fixed element 23. As shown in FIGS. 1 and 3, tape drive arm 24which preferably is of stamped metal, has a plurality of integrallyformed fingers 25, 26, 27 which project transverselyof the feed path ofthe tape T. Finger 25 is substantially parallel to and disposed justabove tape T; Whereas, fingers 26, 27 are below the tape and lie in aplane which intersects the feed path of the tape. A tape drive pawl orpusher is formed of flat spring steel and flexed. slightly in thedirection of arrow 20 by being suitably connected to the inclinedfingers 26, 27 so as to lie substantially in said plane. As illustratedin FIG. 3, this connection is effected by rivets 29 which are carried bythe fingers 26, 27 and project into enlarged key-hole-like apertures inthe pusher.

A central slot 30 provided in the upper end of pusher 28 straddles aprojection 31 extending forwardly, in the direction of arrow 20, fromthe leftmost end of surface 22. This straddling permits the upper end ofthe pusher 28 to contact the bottom of tape T and normally frictionallypinch or squeeze the tape against the under surface 32 of finger 25.Finger 25 has a centrally disposed projection 33 that extends rearwardlyand with lateral clearance between the side edges of a central slot 34(FIG. 3) that is provided in the lower end of a detent 35, for reasonspresently to be described.

Spaced from the guide surface 22 is a fixed element 36 which ispreferably stamped to provide integrally formed fingers 37, 38. Thesefingers, like the fingers 26, 27 of the pusher 28, lie in a planeinclined at an angle to the feed path of tape T. The detent 35 has aconfiguration and composition identical with that of tape drive pusher28 and is secured by rivets 29 to fingers 37, 38 so as to be flexed inthe direction of arrow 20. This detent 35 holds the tape T againstmovement in a direction opposite to that of arrow 20. However, thedetent 35 can flex to permit tape T to be fed in the direction of arrow20 by the tape drive pusher 28 upon movement of the drive arm 24 to alimit position defined by contact with a stop 39. This stop is carriedby a screw 40, which is adjustably positionable in a fixed element andpreferably locked in position by a lock nut 41.

Referring now to FIGS. 1 and 2, the carbon ribbon R is fed through thebite of a pressure roll 42 and a knurled roll 43. Roll 42 is on theinked or carbon wax side of the ribbon. Therefore, it is formed of amaterial, such as polyethylene synthetic material, which does not pickup ink.

Pressure roll 42 is pivotally carried near one end or corner of agenerally triangular support 44 that is rockably mounted on a pin 45. Ahelical toggle spring 46 has one end hooked around a fixed pin 47 andthe other end wrapped around a pin 48 that is carried by the support 44.The support 44 has a manually engageable portion 49 to facilitaterocking of the support to either of two limit positions. In the normalposition, in which the support 44 is shown in solid lines in FIG. 1,toggle spring 46 biases the pressure roll 42 into contact with driveroll 43. In the other limit position, denoted by dotted lines in FIG. 1,spring 46 biases the lower end of the support into contact with a stopsurface 50 to hold the pressure roll 42 a preselected distance away fromroll 43. This toggle action permits the rolls 42, 43 to be held apartmechanically, thus freeing both hands of the operator to facilitateinsertion of a replacement ribbon R between the rolls 42, 43.

Rotation of drive roll 43 and hence the feeding of ribbon R is effectedby a pusher 51 (FIG. 1) which may be rectangular in shape and press fitinto an inclined slot 52 provided in an offset or widened portion of apusher holder 53. To prevent wear, the upper or read edge of the pusher51 preferably abuts the downturned terminal part of an inesrt 54.

It is to be noted that the holder 53 is secured, such as by rivets 55,to the armature 15 so as to be rockable thereby. The tape drive arm 24is welded or brazed to the armature 15.

Summary of Operation Assume initially that the paper tape T is threadedinto the guideway between surface 22 and detent 35 and the overlyingfinger 25 of tape drive arm 24 and pusher 28; that the ribbon R has beenpositioned between rolls 42, 43, in the manner above described, byrocking the support 44, and helped by the toggle action of spring 46;and that electro-magnet is energized. Under these assumed conditions,the various components will be in respective positions in which they areshown in FIG. 1.

When coil 11 is de-energized, spring 17 will rock armature 15counterclockwise and thus correspondingly rock the tape drive arm 24 andholder 53 until said armature strikes stop 39. During this arcuatemovement of arm 24, tape T will be held pinched against the undersurface 32 of finger 25 by the pusher 28; and hence the tape will beadvanced leftward an increment corresponding to the preadjusted degreeof arcuate movement of arm 24. The tape can move leftward because detent35 yields under the pulling force exerted on the tape by the pusher 23.

Meanwhile, as holder 53 moves counterclockwise, it carries pusher 51into jabbing, substantially tangential contact with one of the teeth ofa ratchet wheel 56 for rotating said wheel a predetermined incrementclockwise as viewed in FIG. 1. As ratchet wheel 56 thus moves clockwise,it will, through a shaft 57, rotate the drive roll 43 clockwise acorresponding increment for causing the carbon R to be advanced acorresponding distance leftward through the bite of rolls 42, 43.

When coil 11 is energized, armature 15 will be attracted toward the poleface of core 12 and store power in spring 17. As illustrated, theenergized position of the armature is defined by contact with arotatably adjustable eccentric stop 58. As the armature rocks clockwiseabout pivot 16, it carries holder 53 and thereby retracts pusher 51 fromcontact with the ratchet wheel 56. Meanwhile, tape drive arm 24 will bepulled clockwise by armature 15, for thereby flexing and dragging theupper end of pusher 28 rightward along the under side of tape T whilethe tape is being held stationary by detent 35.

As the overlying finger 25 of arm 24 moves rearwardly over the top ofthe then stationary tape T, buckling of the tape will be prevented. Morespecifically, as arm 24 and hence the overlying rearwardly extendingprojection 33 move rearward over the tape, the tape will be supported onthe forwardly extending stationary projection 31 provided by element 23(see FIG. 3). Thus, the tape is supported over a substantiallongitudinal distance as a result of the overlapping of theseprojections 33, 31; and it is this overlapping which prevents thebuckling. By way of contrast, if no such projections were provided, andthe rear edge of finger 25 and forward edge of surface 22 were straightin a direction transverse to the tape T, the tape would be grippedstrongly enough between the bite of finger 25 and pusher 28 to bucklethe tape between two points: one being at said bite, and the other beingat the forward transverse edge of the detent 35. In such event, thedegree of such buckling would, of course, depend upon the amplitude ofrockable movement of arm 24.

It is to be noted that the central slot 34 in the lower end of detent 35permits the rearward projection 33 of the tape drive arm 24 to moverearwardly of the leading edge of detent 35 to the position in which itsubstantially overlaps the forwardly extending projection 31 of surface22, as shown in FIGS. 1 and 3.

It should also be noted that, unlike previously proposed arrangements,the elements at both sides of the tape (namely, the finger 25 and pusher28) oscillate in unison. This is highly desirable because by grippingand moving forward with the tape, no frictional forces retarding thetape motion are developed at this point. On the other hand, if thefinger 25 were stationary and only the pusher 28 oscillated, it is clearthat the finger would impose a drag that would impede forward motion ofthe tape.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that changes in form and details may be madetherein without departing from the spirit and scope of the invention.

5, What is claimed is: 1. Apparatus'for controlling concurrent feedingof two webs, comprising:

a rockable member providing a finger extending generally atrightanglesto the plane of movement of such member,

a flexible pusher carried by said member and' normally biased towardsaid, finger to frictionally grip opposite sides of one, of. the webstherebetween to move said one, web forward a, selectedincrement duringrocking of said member one way a predetermined amount,

means including adetentfor pressing said one web against a stationarysurface to prevent rearward movement of said web during rocking of saidmember the opposite way,

said pusher being yieldable to permit relaxation of said grip by saidpusher during such rocking of said member said opposite way, and saiddetent being yieldable to permit such forward movement of said one web,

two rolls providing a bite through which the other web is feedable,

another pusher for operatively effecting rotation of one of said rolls aselected amount for advancing said other web a corresponding increment,and

a single actuator operatively connected to said pushers for concurrentlycontrolling their operation and thereby concurrent movement of bothwebs, said finger and stationary surface each having adjacent portionswhich overlap during rocking of said member said opposite way, therebyto minimize buckling of such web as it is held against movement by thedetent-including means.

2. In an apparatus for controlling feeding of a continuous web, thecombination of:

a drive arm rockable between predetermined limit positions,

a pusher carried by said arm for normally pinching the flat dimension ofthe web against a co -operating surface of said arm extending generallyat right angles to the plane of movement of such arm,

means providing a fixed surface, and

a detent normally pinching the web against said fixed surface,

said pusher and detent being flexible and disposed at angles to the webto permit the detent to yield while the web is advanced one way byrocking of the arm and pusher concurrently in one direction, and permitthe pusher to yield and move relative to the web as the pusher and armrock concurrently in the opposite direction and the detent preventsmovement of the web the opposite way,

the co-operating surface of the arm and fixed-surfaceproviding meanseach carrying respective projections which are disposed at oppositesides of the flat dimension of the web and extend generally toward eachother in an overlapping relation to present irregular facing ends onsaid arm and surface-providing means to prevent buckling of the webduring movement of said pusher and arm in said opposite direction.

3. The combination according to claim 2, wherein:

the detent straddles the path of movement of the projection on said armand normally clamps the web between said detent and the fixed surface ata point rearward of the projection provided thereon, and

during movement of said arm in said opposite direction the projectionthereon will extend rearward of such point.

4. Apparatus for feeding a web, comprising means including two laterallyoffset members providing a channel through which the web is feedable,

at least one of the members having a main portion from which aprojection extends toward the other member and is disposed to overlapsuch other member upon movement of said members relatively towardeachother,

a pusher element forclamping the web against a particular one of themembers as the latter. moves relatively away from the remaining member.to cause advancement of the web, and

a, detent element for clamping the web against said remaining member toprevent retrogression of the web as said particular one. member movesrelatively toward said remaining member,

the projection on each member provided therewith being of such lengthand configuration relative to the particular element associated with theother of the two members as to extend up to and beyond the place wherethe said particular element contacts the web, thereby to preventbuckling of the web during movement of said members relatively towardeach other.

5. Apparatus for feeding a web, comprising means including a movablemember and a laterally offset co-operating member providing a channelthrough which the web is feedable,

said members each having respective projections that extend toward eachother from respective main portions and which projections are disposedto overlie each other upon movement of the members relatively towardeach other,

a pusher element for clamping the web against the main portion of themovable member as the latter moves one way to cause advancement of theweb, and

a detent element for clamping the web against the main portion of theco-operating member to prevent retrogression of the web as the movablemember moves the opposite way during a return stroke,

each such element being so configured as to permit the projection on themember associated with the other of the elements to move relatively pastthe place where such element effectively clamps the web against the mainportion of the associated member, thereby to prevent buckling of the webduring such return stroke of the movable member while the web is heldstationary by the detent element.

6. Apparatus for feeding a web, comprising a member movable back andforth between predetermined positions and providing a surface disposedgenerally at right angles to the plane of movement of such member,

a flexible pusher carried by said member and biased toward said surfaceto clamp said web therebetween to move said web forward a selectedincrement during movement of said member one way,

means providing a stationary surface generally parallel to thefirst-mentioned surface, and

a flexible detent for pressing said web against said stationary surfaceto prevent retrogression of said web during movement of said member theopposite way,

the pusher being yieldable to permit it to move relative to the webduring movement of said member said opposite way, and the detent beingyieldable to permit such forward movement of said web,

each of said surfaces having adjacent portions which overlap duringmovement of said member said opposite way, thereby to confine the webfor a substantial portion of its length between said surfaces tominimize bucklng of the web as it is held against movement by thedetent.

7. In an apparatus for feeding a web, the combination means including amovable member and pusher for clamping the opposite sides of the fiatdimension of the web during movement of said member in one direction,for advancing the web one way, and means including another member anddetent for clamping said opposite sides of the web upon movement of saidmember in the opposite direction, for preventing movement of the web theopposite way,

said pusher and detent being flexible and inclined generally said oneway to respectively permit the pusher to be moved said opposite wayrelative to the web and also permit the web to be moved said one wayrelative to said detent,

said movable member and other member having projections which are movedinto overlying relationship with each other when said movable membermoves in said opposite direction, thereby to prevent buckling of the webwhile it is held against movement said opposite way by said detent.

References Cited in the file of this patent UNITED STATES PATENTSGreenbaum et al Apr. 9, 1929 Rosenthal Aug. 9, 1932 Potts Oct. 12, 1948Cooper et a1 Jan. 31, 1956 Garwood Apr. 30, 1957 Schechter July 1, 1958Trimble Dec. 16, 1958 Turner et a1 July 17, 1962

7. IN AN APPARATUS FOR FEEDING A WEB, THE COMBINATION OF MEANS INCLUDINGA MOVABLE MEMBER AND PUSHER FOR CLAMPING THE OPPOSITE SIDES OF THE FLATDIMENSION OF THE WEB DURING MOVEMENT OF SAID MEMBER IN ONE DIRECTION,FOR ADVANCING THE WEB ONE WAY, AND MEANS INCLUDING ANOTHER MEMBER ANDDETENT FOR CLAMPING SAID OPPOSITE SIDES OF THE WEB UPON MOVEMENT OF SAIDMEMBER IN THE OPPOSITE DIRECTION, FOR PREVENTING MOVEMENT OF THE WEB THEOPPOSITE WAY, SAID PUSHER AND DETENT BEING FLEXIBLE AND INCLINEDGENERALLY SAID ONE WAY TO RESPECTIVELY PERMIT THE PUSHER TO BE MOVEDSAID OPPOSITE WAY RELATIVE TO THE WEB AND ALSO PERMIT THE WEB TO BEMOVED SAID ONE WAY RELATIVE TO SAID DETENT, SAID MOVABLE MEMBER ANDOTHER MEMBER HAVING PROJECTIONS WHICH ARE MOVED INTO OVERLYINGRELATIONSHIP WITH EACH OTHER WHEN SAID MOVABLE MEMBER MOVES IN SAIDOPPOSITE DIRECTION, THEREBY TO PREVENT BUCKLING OF THE WEB WHILE IT ISHELD AGAINST MOVEMENT SAID OPPOSITE WAY BY SAID DETENT.